linux/arch/um/os-Linux/skas/mem.c
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   1/*
   2 * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
   3 * Licensed under the GPL
   4 */
   5
   6#include <stddef.h>
   7#include <unistd.h>
   8#include <errno.h>
   9#include <string.h>
  10#include <sys/mman.h>
  11#include "init.h"
  12#include "kern_constants.h"
  13#include "as-layout.h"
  14#include "mm_id.h"
  15#include "os.h"
  16#include "proc_mm.h"
  17#include "ptrace_user.h"
  18#include "registers.h"
  19#include "skas.h"
  20#include "user.h"
  21#include "sysdep/ptrace.h"
  22#include "sysdep/stub.h"
  23
  24extern unsigned long batch_syscall_stub, __syscall_stub_start;
  25
  26extern void wait_stub_done(int pid);
  27
  28static inline unsigned long *check_init_stack(struct mm_id * mm_idp,
  29                                              unsigned long *stack)
  30{
  31        if (stack == NULL) {
  32                stack = (unsigned long *) mm_idp->stack + 2;
  33                *stack = 0;
  34        }
  35        return stack;
  36}
  37
  38static unsigned long syscall_regs[MAX_REG_NR];
  39
  40static int __init init_syscall_regs(void)
  41{
  42        get_safe_registers(syscall_regs);
  43        syscall_regs[REGS_IP_INDEX] = STUB_CODE +
  44                ((unsigned long) &batch_syscall_stub -
  45                 (unsigned long) &__syscall_stub_start);
  46        return 0;
  47}
  48
  49__initcall(init_syscall_regs);
  50
  51extern int proc_mm;
  52
  53int single_count = 0;
  54int multi_count = 0;
  55int multi_op_count = 0;
  56
  57static inline long do_syscall_stub(struct mm_id * mm_idp, void **addr)
  58{
  59        int n, i;
  60        long ret, offset;
  61        unsigned long * data;
  62        unsigned long * syscall;
  63        int err, pid = mm_idp->u.pid;
  64
  65        if (proc_mm)
  66                /* FIXME: Need to look up userspace_pid by cpu */
  67                pid = userspace_pid[0];
  68
  69        multi_count++;
  70
  71        n = ptrace_setregs(pid, syscall_regs);
  72        if (n < 0) {
  73                printk(UM_KERN_ERR "Registers - \n");
  74                for (i = 0; i < MAX_REG_NR; i++)
  75                        printk(UM_KERN_ERR "\t%d\t0x%lx\n", i, syscall_regs[i]);
  76                panic("do_syscall_stub : PTRACE_SETREGS failed, errno = %d\n",
  77                      -n);
  78        }
  79
  80        err = ptrace(PTRACE_CONT, pid, 0, 0);
  81        if (err)
  82                panic("Failed to continue stub, pid = %d, errno = %d\n", pid,
  83                      errno);
  84
  85        wait_stub_done(pid);
  86
  87        /*
  88         * When the stub stops, we find the following values on the
  89         * beginning of the stack:
  90         * (long )return_value
  91         * (long )offset to failed sycall-data (0, if no error)
  92         */
  93        ret = *((unsigned long *) mm_idp->stack);
  94        offset = *((unsigned long *) mm_idp->stack + 1);
  95        if (offset) {
  96                data = (unsigned long *)(mm_idp->stack + offset - STUB_DATA);
  97                printk(UM_KERN_ERR "do_syscall_stub : ret = %ld, offset = %ld, "
  98                       "data = %p\n", ret, offset, data);
  99                syscall = (unsigned long *)((unsigned long)data + data[0]);
 100                printk(UM_KERN_ERR "do_syscall_stub: syscall %ld failed, "
 101                       "return value = 0x%lx, expected return value = 0x%lx\n",
 102                       syscall[0], ret, syscall[7]);
 103                printk(UM_KERN_ERR "    syscall parameters: "
 104                       "0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n",
 105                       syscall[1], syscall[2], syscall[3],
 106                       syscall[4], syscall[5], syscall[6]);
 107                for (n = 1; n < data[0]/sizeof(long); n++) {
 108                        if (n == 1)
 109                                printk(UM_KERN_ERR "    additional syscall "
 110                                       "data:");
 111                        if (n % 4 == 1)
 112                                printk("\n" UM_KERN_ERR "      ");
 113                        printk("  0x%lx", data[n]);
 114                }
 115                if (n > 1)
 116                        printk("\n");
 117        }
 118        else ret = 0;
 119
 120        *addr = check_init_stack(mm_idp, NULL);
 121
 122        return ret;
 123}
 124
 125long run_syscall_stub(struct mm_id * mm_idp, int syscall,
 126                      unsigned long *args, long expected, void **addr,
 127                      int done)
 128{
 129        unsigned long *stack = check_init_stack(mm_idp, *addr);
 130
 131        if (done && *addr == NULL)
 132                single_count++;
 133
 134        *stack += sizeof(long);
 135        stack += *stack / sizeof(long);
 136
 137        *stack++ = syscall;
 138        *stack++ = args[0];
 139        *stack++ = args[1];
 140        *stack++ = args[2];
 141        *stack++ = args[3];
 142        *stack++ = args[4];
 143        *stack++ = args[5];
 144        *stack++ = expected;
 145        *stack = 0;
 146        multi_op_count++;
 147
 148        if (!done && ((((unsigned long) stack) & ~UM_KERN_PAGE_MASK) <
 149                     UM_KERN_PAGE_SIZE - 10 * sizeof(long))) {
 150                *addr = stack;
 151                return 0;
 152        }
 153
 154        return do_syscall_stub(mm_idp, addr);
 155}
 156
 157long syscall_stub_data(struct mm_id * mm_idp,
 158                       unsigned long *data, int data_count,
 159                       void **addr, void **stub_addr)
 160{
 161        unsigned long *stack;
 162        int ret = 0;
 163
 164        /*
 165         * If *addr still is uninitialized, it *must* contain NULL.
 166         * Thus in this case do_syscall_stub correctly won't be called.
 167         */
 168        if ((((unsigned long) *addr) & ~UM_KERN_PAGE_MASK) >=
 169           UM_KERN_PAGE_SIZE - (10 + data_count) * sizeof(long)) {
 170                ret = do_syscall_stub(mm_idp, addr);
 171                /* in case of error, don't overwrite data on stack */
 172                if (ret)
 173                        return ret;
 174        }
 175
 176        stack = check_init_stack(mm_idp, *addr);
 177        *addr = stack;
 178
 179        *stack = data_count * sizeof(long);
 180
 181        memcpy(stack + 1, data, data_count * sizeof(long));
 182
 183        *stub_addr = (void *)(((unsigned long)(stack + 1) &
 184                               ~UM_KERN_PAGE_MASK) + STUB_DATA);
 185
 186        return 0;
 187}
 188
 189int map(struct mm_id * mm_idp, unsigned long virt, unsigned long len, int prot,
 190        int phys_fd, unsigned long long offset, int done, void **data)
 191{
 192        int ret;
 193
 194        if (proc_mm) {
 195                struct proc_mm_op map;
 196                int fd = mm_idp->u.mm_fd;
 197
 198                map = ((struct proc_mm_op) { .op        = MM_MMAP,
 199                                       .u               =
 200                                       { .mmap  =
 201                                         { .addr        = virt,
 202                                           .len = len,
 203                                           .prot        = prot,
 204                                           .flags       = MAP_SHARED |
 205                                           MAP_FIXED,
 206                                           .fd  = phys_fd,
 207                                           .offset= offset
 208                                         } } } );
 209                CATCH_EINTR(ret = write(fd, &map, sizeof(map)));
 210                if (ret != sizeof(map)) {
 211                        ret = -errno;
 212                        printk(UM_KERN_ERR "map : /proc/mm map failed, "
 213                               "err = %d\n", -ret);
 214                }
 215                else ret = 0;
 216        }
 217        else {
 218                unsigned long args[] = { virt, len, prot,
 219                                         MAP_SHARED | MAP_FIXED, phys_fd,
 220                                         MMAP_OFFSET(offset) };
 221
 222                ret = run_syscall_stub(mm_idp, STUB_MMAP_NR, args, virt,
 223                                       data, done);
 224        }
 225
 226        return ret;
 227}
 228
 229int unmap(struct mm_id * mm_idp, unsigned long addr, unsigned long len,
 230          int done, void **data)
 231{
 232        int ret;
 233
 234        if (proc_mm) {
 235                struct proc_mm_op unmap;
 236                int fd = mm_idp->u.mm_fd;
 237
 238                unmap = ((struct proc_mm_op) { .op      = MM_MUNMAP,
 239                                         .u     =
 240                                         { .munmap      =
 241                                           { .addr      =
 242                                             (unsigned long) addr,
 243                                             .len               = len } } } );
 244                CATCH_EINTR(ret = write(fd, &unmap, sizeof(unmap)));
 245                if (ret != sizeof(unmap)) {
 246                        ret = -errno;
 247                        printk(UM_KERN_ERR "unmap - proc_mm write returned "
 248                               "%d\n", ret);
 249                }
 250                else ret = 0;
 251        }
 252        else {
 253                unsigned long args[] = { (unsigned long) addr, len, 0, 0, 0,
 254                                         0 };
 255
 256                ret = run_syscall_stub(mm_idp, __NR_munmap, args, 0,
 257                                       data, done);
 258        }
 259
 260        return ret;
 261}
 262
 263int protect(struct mm_id * mm_idp, unsigned long addr, unsigned long len,
 264            unsigned int prot, int done, void **data)
 265{
 266        struct proc_mm_op protect;
 267        int ret;
 268
 269        if (proc_mm) {
 270                int fd = mm_idp->u.mm_fd;
 271
 272                protect = ((struct proc_mm_op) { .op    = MM_MPROTECT,
 273                                           .u   =
 274                                           { .mprotect  =
 275                                             { .addr    =
 276                                               (unsigned long) addr,
 277                                               .len     = len,
 278                                               .prot    = prot } } } );
 279
 280                CATCH_EINTR(ret = write(fd, &protect, sizeof(protect)));
 281                if (ret != sizeof(protect)) {
 282                        ret = -errno;
 283                        printk(UM_KERN_ERR "protect failed, err = %d", -ret);
 284                }
 285                else ret = 0;
 286        }
 287        else {
 288                unsigned long args[] = { addr, len, prot, 0, 0, 0 };
 289
 290                ret = run_syscall_stub(mm_idp, __NR_mprotect, args, 0,
 291                                       data, done);
 292        }
 293
 294        return ret;
 295}
 296